Apparatus for securing dry steam



April 29, 1952 w. s. PATTERSON 2,594,490

APPARATUS FOR SECURING DRY STEAM Filed Jan. 30, 1948 2 SHEETS-SHEET 1 JNVENTOR.

, Word 8. Patterson mag April 29, 1952 w. s. PATTERSON 2,594,490

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H i I to E g 3Q a rd A h m INVENTOR.

cw Ward 5. Patterson Ll. By

in conjunction wit th saoo ninanyinstdra r gs and water drum of lfigureylzenlagge to l Patented 29, 1952 UNITED PATENT O CE jQRQ E BXNQ DRY STE Wald S. Patterson, Chap aqu y y laszsignpr to .qflmblistion Engineeringhqatmi; Inc a tp ft i n qf Qelaware .7 i

Arnie-annih te ;3 o4s. Se a o- 5 469 1 e, ne I 2 My invention relates to equipment for seem: Figll ffi 5 a simplified section (to reduced ing dry steam from mixtures of steamandwater seale) on line 5-,5 of Figure 2 showing two-rows as taken from the vaporizing surfaces orltubspf of eparat91fu t install-Ed in the u a steam generating boilers, tand itlhas speci 'l rejfr Fjigure 6 is aslecti on on line 6-56 ,of'Figure 2 erence to separator apparatusinstallahle the 5 at cally showing further features of -lthe steam andwaterdrumsofsuchboilerSQtO aeeomvdry-pi ot? apparat benea h d m tfifl plish the purpose named. I pfftalze.

In modern boilers for bothmarine ,and 't' The drum-internalapparatus of iny invention tionary application, the steam and ov ter" m i fispeciaHy well adapted vfor use on forcedeoin usually contains equipment for: 1) ,dis ing 10 3c. i0n;b0 1e rS a d Oi -na cir ula ionlooilers incoming feed water; (2) separatingfsteamfifo'xn hfl iberal tcirc ulatinghead; it may,jr noreover, water; and (3) deliveringstemqvith nimum a antageonsly be employ to tain a high or" entrainment of water or solids. Th 'ge ral degree of steam and water separatibnin steam term drum internals covers this classof equi generators of a Wide variety of types (marine, stament, which has assumed great importance g e l5 tionary or other) and capacities. Illustratiye of the rates of steam liberation-have increased. tthqseris thesteamjg nera r shown inFi ure 1.

Broadly stated, the object of yjinven gs to improve the design, extend the usefulness nd The steam generator of Figuna .1

better the performance of sueh otuminte H a1" het l t a w e x es a e d soharae appamma athi'gh Lvelocity into the drum [0 fromvaporiaing A more specific object is to inerease the q ant -heel;erranaedinfiver wsa-b c d-e (see tity of steam of acceptableefir sswhiolf Figure 2) along the lower right Portion-9f th be taken from a steam and age bfjgwen drum wall; each of these five rows extends lengthdiameter and length. Wise of ho u n co t i a lurality of simi- Another object is to increase t .err eti 25.13 t s; the tub in rows d are ed from a of the steamkfrom-waterseparatingport l .2 'mar :YeP r Zine c u t 14 onsti t ngth the drum-internal equipment. a fipQ 'fi IQQ of e m ti n ham- A further object is to provide;xan irnproyed sep- She -fi e bYv -jburne s l fil fl r w y 'i r arator unit which can readily be a 't'" r er ted iron. s c nd y por n circ t optimum performanceunder Nnetysof; mle fi asomewh igh pa nj nfm tions of steam generatoroperation." f ll lla fi and th tubes i row R areieg A still further object is;-t0 I-increase theefieomi athirdwci i 'l whieh me 2mbU ve s o ne r -pin r q tio r the i (not sh'qwn) eternal equipment.

Additional objects-and advantages will heoome he iillu tat b01191 furnace of i ureapparent from the following -deseri ption 9 us- QIQYid th, y fe at hP tin trative embodiments of v the inyentiomwhe d for m ft Water m u bt 'diseharge outlet 2 into a main distributing-head- Wherein: er 22 and thence through the three vaporizing Figure 1 is asimplified :schernaticerepresentw :P EQ -H earlier a d: .W s-

1 erh ato 2min the he t n pham s t ou ic saturate d. team'leaves drum lfl'py wavof 11.0., let to have itstemperature further 'sedt-boioreen eri g v u oa e. steam heade ea dlwith aninlet' water connectionzfi through toner reed waterisad nitted'into theffd'r'uin a manner later tobe described. Tojla he sis for subsequent description it will Joe asmedr'g-that -thi s '.steam generator of vFigure i ,nejdto op'erLateat re u e un o .2 0 pound Figure 2 is a t transverisfipeo the installed drum-internal apparatus maype constructed inaccordanoe ;with; one;embodiment of the invention;

tion of one of the separator eunitswomptifiiktv i? pa h t d h e alsoethat th 'fi the apparatus ofFigureZ; sepqu ing oircuits14,16 and. i8 are jointly ea- Figure .4 .is .a sectional iview inglicatingl ow pahle of generating steam and passingflsame eachseparator unit ofiEieu-respz ---n ia le- .throush tuh s ln s m and .watorinrum I0 mented by alower,sliroudeand py ndfpr a up'to googooo p uno erin ur;

upper set of; spinner tblades;

heg desor ptionflherjeof proceeds ,it ilbecome apparent that my improved drum-internal apparatus may with comparable benefit also be used with steam generators of either higher or lower capacity and/or pressure and with a wide variety of other types and designs which employ natural as well as forced circulation of the boiler water being vaporized.

The steam and water drum 10 In the illustrative steam generator of Figure l the steam and water drum H] has an internal diameter of 42 inches and a length (see Figures 5-6) of feet between drum ends; the steam I outlet therefrom takes the form of a single pipe leading out of the drum top midway (see Figure 6) of the drum length; the outlet 2| from p the drum bottom takes the form of two downcomer pipes (see Figures 1 and 5) respectively leading out of the two drum ends and acting in parallel to carry the drum-leaving water into pumps 20 (one or more) for circulation through header 22 and boiler vaporizing-circuits I4, I6

and IS; the vaporizing circuit tubes E2 of drumentering rows abcde have an inside diameter of one inch; the end manhole opening into the drum has a horizontal dimension of 16 inches and a Vertical dimension of 12 inches; and

feed water under suitable pressure is admitted by organization just described butmay with comv parable benefit also be installed in steam and water drums of different dimensions, proportions and organizations. I

The drum internals of Figure 2 In the illustrative embodiment of'my invention shown in Figure 2 drum to has installedthere within: (l feed water distributor means which include submerged'pipe 32 perforated as at: 33 and supplemented bywater baflle 34; (2) steamfrom-Water separating means which take the form of centrifugal units 38 projecting upwardly out of the drum water in two 'len'gthwis'e' rows (see Figure 5) along the drum interior and organized to act w en steam and water mixture that enters the drum by way of generator tubes l2 and (3) dry-pipe means 40 for distributing and further drying the steam on its way from separator units 38 to outlet pipe 25 in the drum top.

.flared outwardly at its top into the radial flange The incoming feed water from connection 23 is co-extensive with a major portion of the drum's length. This distributor pipe 32 is closed at both ends and provided along its top with thespaced openings 33 through which all incoming feed water must pass in a way assuring diffusion (aided by baffle plate 34 positioned above admission openings 33 along the entire pipe length) into the main body of the drum water submerging the pipe.

For screening any large particles of solid matway of the two downcomer outlets 2|, each of those outlets has positioned around its open top ter out of the water which leaves the drum by 'useable in combination with the improved separator units 33 and dry-pipe means 40 now to be described.

- Thenew separator units 38 Single-drum boilers (as typified by Figure 1) require very'efiicient and compact means to meet current demands for high capacity and steam purity. In such boilers steam and water mixture entering the drum from tubes 12 may consist of v two to ten parts of water for each one part of steam by weight, but the steam delivered from the drum through outlet 25 preferably should contain as little as two-tenths of one per cent of moisture.

' To provide steam of such dryness the units 38 of Figure 2 are novelly organized to accomplish sparation in three stages. In the first two of these, use is made of centrifugal force and in the third use is made of combined centrifugal force and'low velocity drying.

As illustratively arranged in Figure 2 these new separator units 38 have upwardly passed therethrough from acompartment 42 all of the steam and water mixture that is delivered into the drum [0 by tubes l2; that compartment 42 is enclosed by partition walls 43 which are organized as shown around the ends of tubes l2 and which extend along the entire tube-entering length of the drum to divide the enclosed compartment space from the remainder of the drum interior; and seven separator Lmits 38 constituting a right row are mounted-along horizontal compartment wall 43a while six other similar units 38 constitutinga left row are supported in similar upright position through supply pipes 44 which connect into vertical compartment wall 431).

-It will be obvious that either a lesser or a greater number of units 38 are usable depending upon drum size and quantity of steam to'be separated and that arrangement in less or more than two rows is possible; in fact only a single unit may be found adequate in certain situations.

As here illustratively shown by Figures 2 and 3 each of the units 38 comprises an upright pipe or tube 45 (four inches in diameter here) connected with compartment 42 at its bottom and (3 inches here) sleeve or tube 52 supported (as by welding) from baffle plate 48 above but in concentric relation to upright tube 46 and being provided with outflow slots 5| spaced around its upper edge in-the general manner shown; a flat disc-like member 65 secured (as by welding) to the top of sleeve 52 and deriving support therefrom-while being'open at its center; a plate 58 positioned on top of disc 65 and also open at its center; a second sleeve 62 of further reduced diameter (three inches here) extending downwardly from plate 58 into the first sleeve 52 with an inwardly flaring lower e'dge related 'to the first sleeves outflow water slots in the manner shown by Figure 3; an upper plate 56 supported above lower plate 58 in spaced relation thereto a through bolts and spacers S s-60 (three or'more around the plate circumference); one or more (three shown here) consecutively spaced screens 54 encircling the structure formed by spaced plates 56 and 5B and there supported in part from disc member 65 and in remaining part as indicated; a flared conical fitting 5 attached to the bottom of upper plate 56 (as by the represented stud bolts) and a central rod -53 attached at its threaded top to conical'fitting 54 by adjustable clamp nuts 55 and extending downwardly through sleeve 52 for attachment of its lower end (through threading or otherwise) into spinner '57 for support of same at a selected vertical position within upright tube 46.

The thus constructed unit 38 0f Figures 2 and '3 has an overall height (bottom of tube 46 to top of plate 56) of approximately '16 inches and a diameter for the outer circular screen 64 of approximately 12 inches. Other dimensions and spacings have the proportional relation indicated. As the descriptionzproceeds it will become apparent that other equivalent mechanical constructions are readily possible and that the unit itself may be made either larger or smaller depending upon available drum space and steam separating requirements.

Operation of new separator During normal operation of the steam generator of Figure 1 the water level in drum lll stays close to the drums center line'a's indicated at E6 in Figure 2; and under such conditiorrs'the top edge of upright tube -46 in each separator unit 33 is several inches above the'drum water line while higher parts of the "unit (as screens 64) are'even further above thawate'r'levl. The steam and water mixture entering the-separator units 38 from compartment 42 is preferably passed through a perforated plate 61 suitably positioned in that compartment -(seeFigure"2) to prevent impact of steam-water mixture from evaporator tubes 'l2a-=- b -c on 'the inlet connections to the separator-units 38.

Steam and water mixture passing from compartment 42 upwardly thrmigh the tube 46 of each unit 38 is whirledb'y spinner 4''! so thatupon reaching the tube top the mixture rapidly swirls around the tube interior. The water =con'ten't of the mixture has a density' from four totwentyor more times as great asthe steam content, depending upon the mixture pressure; hence the heavier water thus acted upon by centrifugal force due to the whirlingis concentratednear the wall of upright tube 46 whilethe lighter -'steam is concentrated toward the tube-center. Reduced diameter sleeve 52 (projecting downinto thefiaring top of tube 46) conductsthis :central concentration of steam directly'up through the sleeve and at the same'timeallows the outer concentration of whirling water to pass outside of the sleeve and'radially beneath bafile plate 48 into the drum space (above water level 66) "surrounding unit 33, thisoutfiowingwater-' beingdirected into the main body of drum water by "baffle 48s down-turned brim.

By proper proportionmentof'the annularwaterdischarge space To (see Figure 3') around the "lower-edge of sleeve fiz relative-tozthetotal pastotal water will in this first stage-of separation be skimmed off from the steam and discharged from the unit 38 through space 1-D beneath baffle 48; the central stream of thus partially dried steam (which still contains a small amount of entrained moisture) will thereupon continue upwardly through first sleeve 52 for subjection to the second stage of separating action.

In the illustrative unit 38 of Figures 2-3 said second stage of separation "occurs at outflow slots 5! around the top of first sleeve 52 where the second sleeve 62 projects downwardly thereinto with the small annular spacing shown. iZL'he steam and moisture mixture within sleeve 52 icontinues to whirl during its upward passage therethrough due to the rotary motion earlier 'imparted to the mixture by spinner 41 in tube 16. Result is that the heavier moisture contentof that mixture is thrown outwardly against the wall of sleeve 52, leaving the steam content .;c.oncentrated at the sleeves central portion. Inpro grossing out of the sleeve .52- the (further dried steam thus moves upwardly through :secondssleeve 62 while the wall concentrated-moisture .is skimmed therefrom and passesthrough slots!!! by way of path H out of the separator unit 38:; :this further outflowing Water receiving downward ;direction toward the main body of drum water from impingement with plate 65 and then draining over the down-turned edge of baffle 4.8 therebeneath. Provision of-some mechanical support .for plate 65 other (not shown) than the slot-spacing wall sections of sleeve 52 will enable thatsleevel'to be terminated at the lower edge of slots .51 thereby giving outflow passage H anunobstructedtopen- The third stage of separation by unit 3.8 takes place in the uppermost compartment .and in the circular screens 64. The now nearlydried steam entering this upper compartment through sleeve 62 (in lower plate .58) still retains some of its earlier whirling motion. By that motion steam i s urged in radial flow outwardly toward screens 641, which flow is augmented by the flaring shape of conical fitting 54 and by the pressure within unit iiil; incident to .such radial Jflow, entrained moisture still in the mixture .is .advanced toward the outer edge of lower plate .58, from which edge such moisturedropsdownwardly into the main body of drum water.

The circular screens 64 complete the ".third stage drying by removal of any. remaining J'noisture in the mixture. Such removal is produced by adherence to the screen wiresof themoisture particles and foam film. These .form into water drops which .fiow down the screen sides and drop therefrom (over the outer edge of lower plate 55) into the main body of drum water thereheneath.

The steam-finally emerging from screens fill of unit 38 thus has been successively subjected tea first stage of water separation at the top of upright tube 45; to a secon "stage of water l-separationat the topof sleeve 52; and to a third stage of moisture separationinthesereenassemblage 64 between plates 56 and 58. .Steam thus passed through and-acted upon by each unit sale found to be dried to a remarkably s-highdegree.

The modified separator design of Figure .4

l'spo'sitioned in sleeve 52where\itassuresthatthe 7 steamand'moisture mixture moving upwardly from the tube 45 through that sleeve will rotate with suiiicient rapidity to provide maximum effectiveness in the second and third stages of separate at top sleeve 62 and by circular screens 64. For most applications, however, the primary spinner 47 can be designed satisfactorily to provide all requisite whirling of the steam and water mixture during its full progression through the separator unit 38.

order to reduce foaming and otherwise improve the operation of the separator, each unit 38, as shown byFigures 2-3, may with advantage likewise be provided with a shroud as represented at 82 in Figure 4. This shroud extends downwardlyas shown from the outer edge of screensl pporting plate 65 to somewhat below the normallevel 66 of water in the drum, as indicated by: the dotted outline 82 in Figure 2. By thus surrounding. all of the separator unit parts below'the screen 64 assemblage, this added shroud 82-assures that separated water leaving the unit both at the top of tube 46 and at the top of sleeve 52 will not intermingle with the steam in the generator drums space but instead will be guided directly down into the drum water immediately beneath and around the separator unit.

. Other features of separator design As earlier indicated the mounting of units 38 inside the drum I is such that the top of each upright tube 46 is normally several inches above the drum water level 56 with other unit parts (as screen assemblage 64) even further above the water line. While such relation is desirable, opi crating experience shows that primary separation of water from steam at the top of upright tube 46 willstill be efficient even if baffle plate 48 becomes temporarily submerged due to high Water' level in'the drum. However, base plate 58 of the top screen assemblage 64 should be located high enough in the drum so that it will not become submerged, and in the organizations here represented such requirement is amply met.

The novel separator design here shown has the further advantage of permitting a change in the proportion of discharge openings for both water and steam by the simple operation of substituting a few spacer parts of different length. For example, the area of primary Water passage and the spacing of baflle plate 48 above the top flange of tube 46 may both be reduced by the simple operation of substituting shorter spacers at points 50. This changes the area of both passages named by lowering sleeve 52 with respect to upright tube 46, and permits proportioning the primary water outlet to suit the operating conditions for which the boiler is designed.

The utility of this adjustment will be apparent when it'is considered that the percentage of water in the drum-entering mixture on a volumetric basis is higher in a 1500 pound pressure boiler than in a 500 pound pressure boiler in the ratio of three to one, even when the weight of water in the mixture per pound of steam is the same. It

therefore an important feature of this design increasing the fiow'through passages 10 and H without making any physical change at those points It will accordingly be seen that the separator unit 38 of Figures 24-4 has novel adjustable features which permit a single standard size to be used for a wide variation of operating conditions; moreover, the unit represented as having a diameter of 12 inches for screen assemblage 64 can be fully put together with upright tube 46, spinner 41, baffle plate 48, sleeve 52, central rod 53 andall other parts outside of the drum in and as so fully assembled passed through the drums standard twelve-by-sixteen inch manhole for ready installation or removal as a unit. Attachment to the compartment Wall 43a (right row) or to the supply pipe 44 elbow (left row) may satisfactorilyb through standard screw thread connections as represented so there is very little field assembly work required.

The nezp dry-pipe apparatus In order to distribute and further dry the steam on its way from the several separator units 38 to the single outlet pipe 25 in the top of drum I0, I additionally provide the apparatus generally indicated at in Figure 2 and shown as to further detail in Figure 6. It comprises a V-shaped plate 73 positioned beneath offtake 25 and extending in either direction therefrom for substantially the entire length of the drum but with the two plate edges spaced from the drum top as indicated at 74; a pair of bafiie strips 15 welded along the drum top interior as shown and fu r th er functioning as supports for V-plate 13;

spanning'aportion of the V-plate bottom; and

taper strips 18 adjustably fixed to the sides of V-plate 13 (see Figure 2) and shaped as shown in Figure 6 to give each side steam-admission space M a minimum dimension at the location of steam outlet 25 and a progressively widening dimension as the outlet location is departed from lengthwise of the drum.

Preferably thelV-plate portion beneath screen I! has one or more drain holes 19 passing downwardly therefrom through the plate material (see Figure 6) so that such water as may accumulate in the V-plate may be drained to a point of lower pressure.

Steam leaving the several separator units shown at 38 in Figures 2 and 5 can now pass out of the drum through outlet 25 only by way of openings 14 which direct the steam from both sides (see Figure 2) downwardly along the plate surface and against screen 11. Steam thus entering the V-plate in the drums center beneath outlet 25 (where the admission openings 14 are narrowest) thereupon flows upwardly from the screen and into the ofitake; steam entering the ,V-plate at points removed (lengthwise of the drum-see Figure 6) from the center offtake location (where the admission openings 14 progressively widen) moves lengthwise theretoward The improved dry-pipe apparatus 40 thus not only distributes the steam. in its flow from separator units. 38 out of the drum by way of center oiftaltev 25 but also effects a further separation of entrained moisture therefrom and thereby adds to the dryness of the steam thus finally leaving. the drum.

Moreover, by reason of the tapered shaping of admission openings 14 (see Figures 2v and 6) the natural tendency for steam from the lengthwisedistributed separator units 38 (see Figure 5) to unduly crowd the location of central outlet 25 is minimized and the distributionv efficiency of vplate 13' beneath that outlet is thereby raised.

Performance data The new drum-internal apparatus herein disclosed performs exceedingly well under conditions of practical operation. One test set up for verifying this performance made use of the earlier-described steam generator of Figure l equipped with the 42 inch by 10 foot drum l of Figures 2, 5-6 having positioned therein according to. the plan of Figure 5- thirteen of the separator units 38 of Figures 2-3 and being further provided with the dry-pipe apparatus 40 of Figs. 2 and 6 plus the feedwater and other parts shown.

v The tests were made under a boiler pressure of 1200 p. s. i. Using relatively uncontaminated water in the boiler, the thirteen separator units 38 (each 16 inches tall and 12 inches maximum diameter as earlier described) functioned so effectively that steam containing less than. onequarter of one percent of moisture could be taken from. the single drum outlet 25 at the high rate of 200,000 pounds per hour. This called for delivery of over 15,000 pounds of, dry steam per hour by each of the thirteen separator units 38. Results with boiler water containing solid contaminants in dissolved and suspended form were somewhat less favorable but still very good.

Summary V separator unit which can readily be adjusted for optimum performance under avariety of conditions of steam generator operation; and that I have increased the effectiveness of the dry-pipe portions of the equipment.

My inventive improvements are accordingly capable of wide application and hence are not to be restricted to the specific form here disclosed by way of illustration.

What I claim is: 1. In a steam separator, the combination of an upright tube, means for passing steam and water mixture upwardly through said tube, spinner means in the tube for imparting to said upfiowing mixture a whirling motion which throws water therefrom outwardly againstthe tube wall for discharge from the separator over the tubes top edge and which allows steam from the mixture to flow upwardly out of the tubes central portion, an upright sleeve of smaller diameter than said tube positioned above the tube in substantially spacedly projected into the upper tube end whereby said discharge water passes outside of the sleeve over-the tube top and is thereby separated from said upilowing steam as same passes out of the tubes central portion upwardly through the sleeve interior, an enclosure in communication with the top of said sleeve for receiving the steam issuing therefrom and for directing same radially out of the separator in substantially horizontal flow, and screening means in the path of said horizontal flow for subjecting said separator discharge steam to. a drying action which efiects still further removal of moisture therefrom.

2. In a steam separator, the combination of a first upright tube, means for passing steam and water mixture upwardly through said tube, spinner means in the tube for imparting to said upflowing mixture at whirling motion which throws aportion of the mixtures Water content outward- 13, against the tube wall for spillagefrom the separator over the tubes top edge and which allows the remaining mixture to discharge upwardly from the tubes central portion, a second upright tube of smaller diameter than the first positioned above said first tube in the upward path of said whirling. discharge mixture to collect therefrom on the second tubes inner wall further water for spillage out of the separator over the top edge of that wall, an enclosure at the top of said second tube for receiving the steam issuing there from and for directing same radially out of the separator in substantially horizontal flow, screening means in the path of said flow for subjecting said separator discharge steam to a drying action which effects still further moisture removal, a

conical member depending downwardly from the top wall of said enclosure toward the interior of said second tube in coaxial relation thereto, and means for adjusting the elevation of said top wall and conical member with respect to the second tubesv upper end whereby to vary the area of steam-flow entrance into said screening means enclosure from said second tube and thereby to vary the pressure inside the lower part of the separator. I v

3. In a steam and water drum for a steam gen erator having a steam outlet in the drums upper portion and being provided with a partition dividing the drum interior into a first chamber which is adapted to receive incoming steam and water mixture and a second chamber which is separated from the first and which includes space for steam in the drums upper portion communicating with said, outlet together with an adjoining space in the drums lower portion that is adapted to contain water, the combination of a first generally upright separator tube communieating with the interior of said first chamber and projecting upwardly through the level of the aforesaid water contained within said second chamber into the drums said steam space above said level to convey steam and water mixture from the first chamber into thatsteam space, means in said first separator tube for whirling the steam and water mixture upon upward passage through the tube whereby to separate a major portion of the water content against the tube wall for spilling over the walls top edge into said water space and to allow the whirling mixture thug freed of the separated water to flow further upwardly from the tubes central portion, a second generally upright separator tube of smaller diameter than the first 'positionedabove said first tube in l1 said upward path of the whirling mixture to collect therefrom on the second tubes inner wall further water for spillage over the top edge of that wall and downward flow therefrom to the aforesaid water space, an enclosure communieating with the top of said second separator tube for receiving the steam issuing therefrom and for directing same radially into said steam space in substantially horizontal flow above the aforesaid level of the water in the drums said second compartment, and screening means in the path of said flow for subjecting said steam to a drying action which effects still further moisture removal prior to passage of the steam out of the drum by way of said outlet.

4. In a steam and water drum for a steam generator having a steam outlet in the drums upper portion and being provided with a partition dividing the drum interior into a first chamber which is adapted to receive incoming steam and water mixture and a second chamber which is separated from the first and which includes space for steam in the drums upper portion communicating with said outlet together with an adjoining space in the drums lower portion that is adapted to contain water, the combination of a first generally upright separator tube communicating with the interior of said first chamber and projecting upwardly through the level of the aforesaid water contained within said second chamber into the drums said steam space above said level to convey steam and water mixture from the first chamber into that steam space, means in said first separator tube for whirlin the steam and water mixture upon upward passage through the tube whereby to separate a major portion of the water content against the tube wall for spilling over the walls top edge into said water space and to allow the whirling mixture thus freed of the separated water to fiow further upwardly from the tubes central portion, a, second separator tube of smaller diameter than the first positioned above said first tube in said upward path of the whirling mixture to collect therefrom on the second tubes inner wall further'water for spilling over the top edge of that wall, a bafiie plate extending outwardly from above the top of said second separator tube, a skirt extending downwardly from said baffle plate around both said first and second tubes to below the aforesaid level of the water in said drums lower portion and aiding the baffle plate in con fining flow of spillage water from both of the tubes downwardly around the first-tube exterior, and screen means communicating with the top of said second separator tube for subjecting the steam issuing therefrom to a drying action which effects still further moisture removal prior to passage of the steam out of the drum by way of said outlet.

5. In a steam and water drum for a steam generator having a steam outlet in the drums upper portion and being provided with a partition dividing the drum interior into a first chamber which is adapted to receive incoming steam and water mixture and a second chamber which is separated from the first and which includes space for steam in the drums upper portion communicating with said outlet together with an adjoining space in the drums lower portion that is adapted to con- 12 tain water, the combination of a first generally upright separator tube communicating with the interior of said first chamber and projecting upwardly through the level of the aforesaid water contained within said second chamber into the drums said-steam space above said level to convey steam and water mixture from the first chamber into that steam space, means in said separator tube for whirling the steam and water mixture upon upward passage through the tube whereby to. separate water from the mixture against the tube wall for spilling over the walls top edge and discharge therefrom into the drums said water space and to allow steam from the mixture to continue upwardly out of the tubes central portion, a second separator tube of smaller diameter than the first positioned above said first tube in substantially coaxial relation thereto with the lower end of the second tube spacedly projected into the upper end of the first tube whereby said discharge water passes over the first tube top outsidepf said second tube and is thereby separated-from said upfiowing steam as same passes from the first tubes central portion upwardly through the second tube interior, baffle means extending outwardly from said second tube spacedly above the top of said first tube, a skirt extending downwardly from said baffl means around both said first and second tubes to below the aforesaid level of the water in said drums lower portion whereby to confine the aforementioned discharge water from the first tube top to downward flow within the skirt into the drum water immediately around the first tube exterior, an enclosure above said baflie means communicating with the top of said second tube for receiving the steam issuing therefrom and for di. recting same radially into the drums said steam spacein substantially horizontal flow above the aforesaid level of the water in the drums said second compartment, and screening means in the path of said flow for subjecting said steam to a 'drying action which effects still further moisture removal= prior to passage of the steam out of the drum by way of said outlet.

WARD S. PATTERSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 767,721 Swartwout Aug. 16, 1904 791,517 Walker June 6,1905

1,708,656 Bradshaw Apr. 9, 1929 2,059,521 Hawley Nov. 3, 1936 2,063,425 Fletcher Dec. 8, 1936 2,139;985 Tafl Dec. 13, 1938 2,289,970 Rowand et al July 14, 1 42 2,297,704 Huge Oct. 6, 1 42 2,320,345 Blizard June 1, l 43 2,346,672 Fletcher Apr. 18, 1944 2,368,211 Fletcher Jan. 30, 1945 2,368,632 Blizard Feb. 6, 1945 2,395,855 Fletcher -2 Mar. 5, 1946 FOREIGN PATENTS Number Country Date Y 172,838 Great Britain Dec. 22, 1921 

